Changing from the property from Mass fraction to substance fraction has not effect on the meaning when the molecular weight of the numerator and the denominator are the same (for practical purposes). These terms had had a property of MFR in the past and we changed to SFR because we thought the LOINC community preferred SFR for HbA1c. But we mis understood the preference is to use the MFR variant- so we have changed back.

Common Test Rank

81

Common Order Rank

48

Common SI Test Rank

81

Detailed Information

Field Name

Field Value

Field Description

LOINC Number

4548-4

The unique LOINC Code is a string in the format of nnnnnnnn-n.

Component

Hemoglobin A1c/Hemoglobin.total

First major axis-component or analyte

Property

MFr

Second major axis-property observed (e.g., mass vs. substance)

Time Aspect

Pt

Third major axis-timing of the measurement (e.g., point in time vs 24 hours)

An arbitrary classification of the terms for grouping related observations together. The current classifications are listed in Table 29. We present the database sorted by the class field within class type (see field 23). Users of the database should feel free to re-sort the database in any way they find useful, and/or to add their own classifying fields to the database.
The content of the laboratory test subclasses should be obvious from the subclass name.

ACTIVE = Concept is active. Use at will.
TRIAL = Concept is experimental in nature. Use with caution as the concept and associated attributes may change.
DISCOURAGED = Concept is not recommended for current use. New mappings to this concept are discouraged; although existing may mappings may continue to be valid in context. Wherever possible, the superseding concept is indicated in the MAP_TO field in the MAP_TO table (see Table 28b) and should be used instead.
DEPRECATED = Concept is deprecated. Concept should not be used, but it is retained in LOINC for historical purposes. Wherever possible, the superseding concept is indicated in the MAP_TO field (see Table 28b) and should be used both for new mappings and updating existing implementations.

Cosumer Name

Hemoglobin A1c (Glycated)

An experimental (beta) consumer friendly name for this item. The intent is to provide a test name that health care consumers will recognize; it will be similar to the names that might appear on a lab report and is not guaranteed to be unique because some elements of the LOINC name are likely to be omitted. We will continue to modify these names in future release, so do not expect it to be stable (or perfect). Feedback is welcome.

Molar Mass

16500

Molecular weights: This field contains the molecular weights of chemical moieties when they are provided to us. This release contains values kindly contributed by IUPAC.

Class Type

1

1=Laboratory class; 2=Clinical class; 3=Claims attachments; 4=Surveys

Units Required

Y

Y/N field that indicates that units are required when this LOINC is included as an OBX segment in a HIPAA attachment

This is a new field introduced in version 2.05. It contains synonyms for each of the parts of the fully specified LOINC name (component, property, time, system, scale, method). It replaces #8, Relat_NMS.

Short Name

Hgb A1c MFr Bld

Introduced in version 2.07, this field is a concatenation of the fully specified LOINC name. The field width may change in a future release.

Order OBS

Both

Defines term as order only, observation only, or both. A fourth category, Subset, is used for terms that are subsets of a panel but do not represent a package that is known to be orderable we have defined them only to make it easier to maintain panels or other sets within the LOINC construct.

CDISC Commont Test

Y

“Y” in this field means that the term is a part of subset of terms used by CDISC in clinical trials.

Example Units

%

This field is populated with a combination of submitters units and units that people have sent us. Its purpose is to show users representative, but not necessarily recommended, units in which data could be sent for this term.

Long Common Name

Hemoglobin A1c/Hemoglobin.total in Blood

This field contains the LOINC term in a more readable format than the fully specified name. The long common names have been created via a table driven algorithmic process. Most abbreviations and acronyms that are used in the LOINC database have been fully spelled out in English.

HL7 v2.x Data Type

NM/ST

HL7 version 2.x data type that would be sent in OBX-2 when this data is delivered in an HL7 message.

HL7 v3.x Data Type

PQ

HL7 version 3.0 data type that is compatible with this LOINC code.

Curated Rande and Units

3.8-6.4;%

A curated list of normal ranges and associated units (expressed as near UCUM codes) for physical quantities and survey scores. Intended as tailorable starter sets for applications that use LOINC forms as a way to capture data. Units are separated from normal ranges by XXX and sets of normal range/units pairs are separated by YYY.

Example UCUM Units

%

The Unified Code for Units of Measure (UCUM) is a code system intended to include all units of measures being
contemporarily used in international science, engineering, and business. (www.unitsofmeasure.org ) This field contains example units of measures for this term expressed as UCUM units.

Change Reason

Changing from the property from Mass fraction to substance fraction has not effect on the meaning when the molecular weight of the numerator and the denominator are the same (for practical purposes). These terms had had a property of MFR in the past and we changed to SFR because we thought the LOINC community preferred SFR for HbA1c. But we mis understood the preference is to use the MFR variant- so we have changed back.

Detailed explanation about special changes to the term over time.

Common Test Rank

81

Ranking of approximately 2000 common tests performed by laboratories in USA.

Common Order Rank

48

Ranking of approximately 300 common orders performed by laboratories in USA.

Common SI Test Rank

81

Corresponding SI terms for 2000 common tests performed by laboratories in USA.